Vehicle door latch



Aug 1937. c. s. BURNETT 2,091,266

VEHI CLE DOOR LATCH Filed Sept 15, 1933 Jay 1 Ind/672 207 [/2 SEW/285i @y M Patented Aug. 31, 1937 3 UNITED STATES VEHICLE DOOR LATCH Charles S. Burnett, San Francisco, Calif.

Application September 15, 1933, Serial No. 689,599

2 Claims.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3'70 0. G. 757) This invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention generally relates to door latches but more specifically to the type of door latch used on automobile doors, which are controlled by outside and inside door handles.

One object of the invention is to provide a door latch so constructed that the outside door handle may be rendered ineffective in operation in order to bafile an intruder or thief; who, when attempting to unlock the door by twisting the handle will not in any way damage the lock or latch mechanism.

Another object is to provide a latch which may be easily operated from inside the car, so that any tampering with the outside control handle will be ineffective in unlocking the same.

It is known that locks now in use are so designed in construction that the spindles of the outside door handles can be broken by twisting without disturbing the latching mechanism, but this inconveniences the owner of the car and subjects him to expense for repairs.

Briefly stated, the lock which forms the subject matter of this invention is so constructed that when the inner handle is turned in a clockwise direction, the outer handle may be twisted or revolved in either direction without effecting movement of the bolt, since all connections between the outer handle and the locking mechanism are out of engagement and the handle is free to rotate.

Referring more particularly to the accompanying drawing in which corresponding parts are indicated by similar reference characters:

Fig, 1 is a perspective view, partially in section, of one form of locking mechanism showing the principal operating parts;

Fig. 2 is a side view partially in section of an outer control handle showing the radially sliding key which engages the operating cam;

Fig. 3 is a side view partially in section of the modified form of handle and spindle which contains the lock and shows the connection between the locking mechanism and the operating cam;

Fig. 4 is an enlarged end view of a lock handle spindle, showing the lock operated cam key in disengaged position;

Fig. 5 is a similar view to Fig. 4, showing lock operated cam key in engaged position;

Fig. 6 is a side view of a locking yoke for automobile door latches having the locking mechanism located remote from the door handle.

Referring particularly to Fig. l, the numeral (I0) indicates a casing in which the latching mechanism is mounted. This casing is constructed with side walls (I I) and (I2), end

walls (l3) and (M), a top (IS), a bottom (l6) and a partition (IT).

A bolt mechanism is mounted centrally within the casing and is supported by the end walls (It) and (i4) and the partition through which it passes. The bolt mechanism comprises the following members: a reciprocating bolt (l8) operated directly by a cam (|9) rotatably mounted on the spindle (2Q) of the outer door handle, and a reciprocating sleeve (2|) slidably mounted on said bolt (l8) and operated directly by a cam (22) rigidly attached to the spindle (23) of the inner bolt handle. The bolt (it) is constructed with a central body portion (24) preferably of circular cross-section, having a forward bearing member (25) of square cross-section terminating in a beveled nose (28), and a rearwardly extending circular shaft (2?) of smaller diameter than the body (2%). The forward squared bearing member (25) is slidably fitted within a square opening (9) in the end wall (Id) of the casing and the rear shaft (27) is slidably mounted within the sleeve (2|).

The sleeve is constructed with a forward re duced cylindrical bearing member (28) which slidably fits within a circular opening (8) in the partition (H), and receives the rear shaft (2?) of the bolt. Adjacent the forward portion of the sleeve is the rear cylindrical body member (29) of greater outside diameter which abuts against the partition (ll) at its forward end and is slidably fitted within a circular opening (l) in the end plate (l3).

Encircling the reduced bearing portion (28) of the sleeve (2|) and the similarly reduced rearward shaft (27) of the bolt (I8) is a helical spring (til), which reacts against the partition (I1) and the end of the central enlarged body portion (24) of the bolt, to move the latter to the right into locking position.

The extended rear shaft (2?) of the bolt (l3) passes entirely through the sleeve (2|) and is threaded at its end for reception of the two lock nuts (3|) and (32) which serve as a means for adjusting the compression of the spring (30) and the amount of projection of the nose (23).

Both the bolt (I8) and the sleeve member (2|) are formed with lateral projecting lugs (33) and (34) which are formed integrally with the body portions of these members and are positioned adjacent the operating cams (l9) and (22), so that both bolt and sleeve member will be moved to the left when the cams are rotated in a counter clockwise direction.

These cams (l9) and (22) are mounted respectively on the spindles (2(3) and (23) of the outer and inner door handles as stated above. For the sake of clearness these handles are omitted from Fig. 1.

Pivotally mounted on the rear operating cam,

to which the inside handle is attached are links (35) and (3%) which are forked at their forward ends as shown in Fig. 1. These links passing through an opening (3?) in the partition (H), are alike in form and constructed in the following manner. The upper prong (58) of the fork (E0) is constructed with a downwardly projecting cam surface (38) which slides over a movable key (35) mounted in the spindle (20) of the outer door handle as shown in Fig. 2. The key (39) is mounted within a slot (M) cut in the spindle (29) and is supported by two helical springs ll) and (42). The key (39) is formed with extending lugs 13) and (Mi) projecting beneath the screws (35) and (iii) which serve to retain the key (39) within the slot (till) against the action of the springs. The operating cam (i9) is rotatably mounted on the spindle (2D) and is provided with a keyway (4?) for the reception of the key (25%), which forms a means of engagement between the spindle (28) and the cam (i9), so that the spindle and cam may be rotated as a single unit.

When desired the spindle (20) of the outer handle may be thrown out of engagement with the cam (i6) by the clockwise rotation of the inner handle which rotates the cam (22). The rotation of this cam (22) pulls the links (35) and (36) to the left until the cam projection (38) on the lower surface of the upper prong Eli) and the corresponding cam surface of the prong of the link (3%) (on the opposite side of the cam (l9) not shown) ride up on the key (35) depressing the same and permitting the spindle (2i!) and the outer door handle to rotate without movement of the cam (IS).

The engaging mechanism between the spindle (2E) and the cam (59) as constructed in a looking handle is shown in Fig. 3. In this figure the space designated by the numeral E8) is for the lock which does not form any part of this invention, so for the purpose of clearness is entirely omitted. The shaft (59) which is mounted within the spindle (52) is rotated when the key is turned within the lock, and a radial movement is imparted. to the cam key (59) through the yoke (5!) which is mounted on the eccentric pin (52). (See Figs. 3, 4 and 5.) Thus if the key of the look (not shown) is turned so that the cam key (59) projects above the circumference of the spindle (62) it engages the key-way il in the cam (l9), and the spindle and cam operate as a unit, so that a turn of the handle (53) rotates the cam (iii) and moves the bolt (It) against the action of the spring (33) thus unlocking the door.

When the cam key (59) does not project beyond the circumference of the spindle (62) it cannot engage the keyway (41) of the cam (l9) and therefore turning of the outer door handle (58) in either direction will not efiect movement of the bolt (58), which remains in locked position due to reaction of the spring (3L In the door mechanism which contains the lock it is not necessary to include in the construction the links (35) and (35) to release the cam (E9), since the cam key (59) is retracted by the lock mechanism to render the handle in idling relation to the bolt (i8) and thus latch the door. In this type of mechanism, the door may be unlatched by the inside handle which retracts bolt (it) through the action of the cam (22).

When the locking mechanism is not located in the door handle but placed in some adjacent position in the door, a mechanism as shown in Fig.

6, may be used for engaging and disengaging the outer door handle spindle from the bolt cam. In this mechanism a forked cam member (93) is used to retract the keys (66) and (8'1) of the spindle (68) in the same manner that cam surface (38), of the upper prong (58) of fork (as shown in Fig. 1), retracts the movable key (39) which is mounted in the spindle (28) The fork is operated by an accentric (69) on the shaft (N) which is rotated by turning the key in the look. It will be noted that cam G9), which is shown in Fig. 6, is provided with two keyways for the reception of keys (66) and (67); otherwise cams (59) and H9) are of similar con struction. Neither the lock nor key is shown in the figure.

Having described my invention, what I claim as new and wish to secure by Letters Patent is:

l. A latch mechanism comprising a housing, a bolt slidable within the housing and provided with a laterally projecting lug, a spring adapted to normally retain the bolt in latching position, an outside operating means adapted to retract the bolt against the action of the spring, said outside operating means including a rotatable spindle provided with a slot, a depressible key positioned within and normally projecting above said slot, said key being formed with a laterally extending shoulder, means to retain said key in its normal position, a cam mounted upon the spindle and formed with a keyway to receive said key, said cam coacting with the lug on the bolt to retract the latter; an inside operating means for rendering the outside operating means ineffective for retracting the bolt, said means comprising a rotatable member, a longitudinally movable link pivotally connected at one end to said rotatable member, the opposite end of said link being bifurcated, the furcations engaging one end of said spindle, and a cam surface formed on one of the furcations of said fork and coacting with the laterally extending shoulder on said key, to depress the latter and disconnect the spindle and cam when longitudinal movement has been imparted to the link by operation of the rotatable member.

2. A latch mechanism comprising a housing, a bolt slidable within the housing and provided with a laterally projecting lug, a spring adapted to normally retain the bolt in latching position, an outside operating means adapted to retract the bolt against the action of the spring, said outside operating means including a rotatable spindle provided with a slot, a depressible key positioned within and normally projecting above said slot, said key being formed with a laterally extending shoulder, means to retain said key in its normal position, a cam mounted upon the spindle and formed with a keyway to receive said key, said cam coacting with the lug on the bolt to retract the latter; an inside operating means for rendering the outside operating means ineffective for retracting the bolt, said means comprising a rotatable member, a longitudinally movable link pivotally connected at one end to said rotatable member, and means in connection with the free end of said link and coacting with the laterally extending shoulder on said key to depress the latter and disconnect the spindle and cam when longitudinal movement has been imparted to the link by operation of the. rotatable member.

CHARLES S. BURNETT. 

